Abrasive element and method of making same



w. J. ELLIS 2,038,782 ABRASIVE ELEMENT AND METHOD OF MAKING SAME April28, 1936.

Original Filed May 16, 1951 U m/ 1 :T OJ u .i. 1 1 8 :1 i 7 in INVENTOR.

ZJz'Z/z'am I 6772';

A TTORNEYS Patented Apr. 28, 1 93 6 ABRASIVE LELEMENT MAKING AND METHODOF SAME William'J. Ellis, Los Angeles, Calif., assignor to Hazel J.Ellis, Los Angeles, Calif.

Application May 16,1931, Serial No. 537,792 Renewed November 7, 1935 9Claims.

which has been wrapped a strip of abrasive-cov-' ered fabric. It has nowbeen discovered that the mandrel and the abrasive surface may be formedin'a single operation with consequent increased production and reducedcosts. These abrasive elements are used in surfacing articles of metaland wood, castings, etc;, such articles often having curved surfaceswhich it is desired to treat with the abrasive. A revolving cylindricaltube or sleeve does not fit into these curved surfaces very well and itis also desired to provide an abrasive element which shall conform tothe surface being treated.

It is accordingly an object of the invention to provide a method ofmaking tubular abrasive elements in an improved and economical manner.Another object of the invention is to provide a 43 method formanufacturing these. elements in'a strong and durable form and in asingle process. A further object of the invention is to provide anabrasive element of sturdy construction molded to conform to curvedsurfaces which are to be treated and which will retain its shape underthe stresses encountered during use. To the. accomplishment of theforegoing and related ends, said invention, then, consists of the meanshereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexed drawing:

Fig. 1 is a diagrammatic view showing the method of forming abrasiveelements; Fig. 2 is a perspective of a tubular element built up by thenew method with the various layers exposed;

Fig. 3 is a perspective of a complete element with mandrel and abrasivelayers in place; Fig. 4 is a view showing one modification of a moldedtubular element; Fig. 5 is a view of another modification; Fig. 6 is aview of a tubular element having molded ends.

Referring to Fig. 1, a series of rolls 1, 8, 9 and III are mounted on ashaft I I. These rolls, which may vary in number from that shown, carrystrips of fabric l2, l3, l4 and I5 suitable to be built up into atubular abrasive element, for example, strips l 2 and l 3 may consist ofchipboard or kraft paper suitable to form a mandrel, while strip I! maybe of kraft paper to form an inner or supporting 5 sleeve and strip I5will consist of paper with an abrasive coating to form the outer surfaceof the abrasive element. I do not desire to be limited to the materialsnamed, it being understood that cloth may be used as well as variouskinds of 10 paper for any of the layers mentioned provided the outerlayer bears an abrasive coating.

The various strips are fed from the rolls onto a mandrel I6 and arespiraled thereon, the mandrel strips I2 and [3 being wrapped first toform 15 a permanent mandrel for the abrasive element and the strip l5being wrapped last to form the abrasive surface. Adhesive is supplied tothe various stripsin order that they will adhere in a strong andpermanent fashion. The element is 2o pushed off the mandrel l6 as fastas it is formed, the process'thus being continuous in character. Thevarious strips may overlap each other in order to stagger the seams andthus increase the strength of the finished article. If a cylindrical 25abrasive element is desired, the tube may be cut off in suitable lengthsas it is formed.

A section of the abrasive element so formed is shown in Fig. 2 in whichthe element I l is shown as consisting of a mandrel in two layers l8 and30 I9, although this may be formed in one layer or in many layers ifdesired by omitting one of the rolls I and. 8 or increasing thenumber'of such rolls. Over the mandrel may be placed the inner orsupporting sleeve 2| although this also 35 may be omitted. The outermostlayer 22 bears the surface of abrasive particles which is to be used insurfacing operations. Fig. 3 shows a finished cylindrical abrasiveelement 29 with mandrel, sleeve and abrasive layers. 0

As above mentioned, it is often desired to treat articles having curvedsurfaces and it is highly desirable to provide a surfacing element whichwill conform to the surface of the work being treated. Fig. 4 shows asurfacing element 24 45 having a convex surface 25 adapted to treat con-.cave surfaces where encountered, while Fig. 5

shows a surfacing element 26 having a concave surface 21 adapted totreat convex surfaces where encountered. 50

The desired contour is imparted to the cylindrical element formed in theabove method either immediately after the formation of the cylinderwhile the adhesive is still soft and the element still moldable or, theelement may be moistened 55 .or placed in a steam box, and then molded.

' shapes thus imparted to the abrasive elements will be surfaces ofrevolution since the element is,

The

to be applied while rotating to the curved surfaces of the work undertreatment. It will be obvious that any desired contour may be im- I ofthe seam will not be encountered by the work.

4 cal thereto.

parted, those shown on the drawing being merely illustrative.

While the tubular element is being molded, I have found it desirablealso to mold the ends of the section in order to bend these slightlyinward toward the axis of the tube although, of course,

desired, only the ends need be molded, this being a special case wherea-cylindrical element is under the general method. My purpose in thusmolding or turning in the ends of the-cylinder is to avoid tearing orripping the abrasive element which often encounters sharp corners whenapplied, while rotating, to the. work, the edge or corner encounteredbeing likely to catch the seam 28. If the ends are bent inward as at 29,the end By building up the entire element, including the .mandrel andabrasive surface, in one operation,

the molding step may .be carried out on the newly formed tube while itis still plastic, before any of the adhesive necessary to form the tubehas set.

The present method of making an abrasive sleeve or element by formingthe mandrel simultaneously with the abrasive surface results inincreased speed of production and lower cost while the abrasive elementshaving surfaces molded to conform to the work being treated are muchmore eflicient and cut down the cost of surfacing articles treatedthereby. v

Other modes, of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means' stated by any of the followingclaims or the equivalent of such stated means be employed.

1- therefore particularly point out and distinctly claim as myinvention:

1. A method of making abrasive elements which comprises forminga mandreland permanently uniting an abrasive covering thereto in one continuousoperation and then molding the same under pressure. I

2. A method of making abrasive elements which comprises winding fabricstrips to form a mandrel andimmediat'ely winding an abrasive strip oversaid mandrel strips in one continuous operation and then subjecting saidelement to a molding operation under pressure.

3. A method of making abrasive elements which comprises simultaneouslywinding man-.- drel strips and anabrasivestrip to form a compositeabrasive element and then softening said element and molding the same toimpart a surface of revolution thereto.

4. A method of making abrasive elements which comprises simultaneouslywinding mandrel strips and an abrasive strip to form a-compositecylindrical abrasive element and then molding the same, while theadhesive used is soft, to impart a surface of revolution other thancylindri- 5. A method of making tubular abrasive velements whichcomprises forming a. cylindrical abrasive tube and then. molding thesame under pressure.

6. A method of making an abrasive'element which comprises forming atubular abrasive ele-- ment and then compressing the same to impart asurface ofrevolution thereto.

7. In the method of making an abrasive element the step which comprisesmolding a tubular

